355brushless Machine Drive

The machine drive consists of a polyphase, rotating field stator, a permanent magnet rotor, a rotor position sensor, and the electronic drive. During operation the electronic drive, according to the signals received from the rotor position sensor, routes the current in the stator windings to keep the stator field perpendicular to the rotor permanent field, and consequently generates a steady torque. Conceptually, the drive operates as the commutator of a DC machine where the brushes are eliminated. The main advantage here is that no current flow is needed in the rotor. As a result, rotor losses and overheating are minimal, the input power factor approaches unity and maximum efficiency is obtained. This is especially relevant in continuous duty applications, where the limiting factor of traditional induction drives is invariably the difficulty of removing rotor losses.

Fig. 3.9 Machine controller.
0 0

Post a comment